There is typically regression to the mean, but every now and then the athletic genes are passed on in full.
I think about the 2006 and 2007 Florida basketball teams, which had an usual number of legacy players. The point guard was Taurean Green, son of NBA forward Sydney Green. Taurean only got a cup of coffee in the NBA, but is still playing overseas. There was Al Horford, whose dad Tito played in the NBA - of course Al's brother was not nearly as good as Al. Then there was Joakim Noah, whose dad was the great tennis player Yannick Noah.
Soccer, of course, depends more than most sports on technical skill developed over repeated practice, rather than just raw athleticism. That may favor the child of a professional soccer player, who may be well developed by all the talent and focus at home. Christian Pulisic is a guy who comes to mind.
Nevertheless, my guess is that the child of a professional soccer player is only about 10% or so to make a living playing the same sport.